End posture analysis and motion planning based on UR3 manipulator puncture navigation / 国际生物医学工程杂志

Objective:To establish a motion planning method for avoiding singularities for manipulator-assisted puncture surgery navigation, and design the corresponding computer program.Methods:According to the actual operation and the need of clinicians, the puncture needle sleeve installed at the end of the UR3 robotic arm was designed, and the kinematics analysis and simulation verification of the robotic arm were performed. A calculation program for solving the movement pose when the puncture needle at the end of the robotic arm reaches the target position, and a motion planning program for avoiding singularities through small-angle rotation were programmed.Results:Six groups of joint angles were randomly selected, and the theoretical coordinates calculated by the program were compared with the actual coordinates. The result showed that the error between the theoretical value and the actual value was small, which proved the correctness of the kinematics model. In the verification experiment, 3 sets of initial poses at random were simulated, the best pose was obtained by the program. Then the pose was transmitted into the control system to control the movement of the robotic arm. The verification experiment results showed that the puncture needle can reach the target point, and the singularity can be effectively avoid by the small-angle rotation of the fixed central axis.Conclusions:The singular point avoidance method based on end posture rotation can effectively avoid the failure of initial target posture motion planning, and it has reference value for the application of manipulator in puncture surgery.

Function, structure and catalytic mechanism of sucrose phosphate synthase: a review / 生物工程学报

Sucrose is a natural product occurs widely in nature. In living organisms such as plants, sucrose phosphate synthase (SPS) is the key rate-limiting enzyme for sucrose synthesis. SPS catalyzes the synthesis of sucrose-6-phosphate, which is further hydrolyzed by sucrose phosphatase to form sucrose. Researches on SPS in recent decades have been focused on the determination of enzymatic activity of SPS, the identification of the inhibitors and activators of SPS, the covalent modification of SPS, the carbohydrate distribution in plants regulated by SPS, the mechanism for promoting plant growth by SPS, the sweetness of fruit controlled by SPS, and many others. A systematic review of these aspects as well as the crystal structure and catalytic mechanism of SPS are presented.

Design of a portable nitric oxide rescue device / 国际生物医学工程杂志

Objective:To design a portable NO rescue device that can be used for NO inhalation therapy.Methods:The NO rescue device adopts a modular design, and the key parameters can be easily adjusted. The device uses a low-intensity, high-frequency pulse discharge method to produce NO mixed gas by ionizing dry air at atmospheric pressure, and uses Ca(OH) 2 particles to filter the NO 2 gas in the NO mixed air. Based on the NO rescue device, the effects of airflow direction, gas flow rate and input voltage on the levels of NO and NO 2 in the NO mixed gas were studied. The NO 2 filtering performance of the NO 2 removal device in the device was also studied. Results:When the air flows in from the cathode and flows out from the anode of the reaction chamber, and the flow rate and input voltage respectively were 2 L/min and 4 V, the system had a better performance. At this condition, the volume fraction of NO in the output gas is 3.25×10 -5, and NO 2/NO is about 0.05. Conclusions:The proposed NO rescue device can meet the needs of medical NO gas, and the system has stable performance, portable volume, and low cost, and has broad application prospects in the treatment of pulmonary hypertension and chronic obstructive pulmonary diseases.

Research progress of medical nitric oxide production technology / 国际生物医学工程杂志

Nitric oxide is a messenger molecule in the body, which is widely distributed in various tissues of living organisms and participates in regulating the physiological activities of cells. Inhalation of low concentrations of NO can selectively relax the pulmonary blood vessels, which can achieve good results and has been applied in clinical respiratory emergency treatment such as pulmonary hypertension, neonatal hypoxic respiratory failure, acute respiratory distress syndrome (ARDS), etc. At present, in addition to the clinical use of chemical methods to produce NO gas (storage in cylinders), NO can also be generated by discharge. Among them, the pulsed arc discharge can realize the preparation of NO at any time and solve the problems of decompression and storage of conventional NO gas supply. In this paper, the clinical application of NO, discharge technology, and removal methods of nitrogen dioxide (NO2) were reviewed.

Research progress of medical nitric oxide production technology / 国际生物医学工程杂志

Nitric oxide is a messenger molecule in the body, which is widely distributed in various tissues of living organisms and participates in regulating the physiological activities of cells. Inhalation of low concentrations of NO can selectively relax the pulmonary blood vessels, which can achieve good results and has been applied in clinical respiratory emergency treatment such as pulmonary hypertension, neonatal hypoxic respiratory failure, acute respiratory distress syndrome (ARDS), etc. At present, in addition to the clinical use of chemical methods to produce NO gas (storage in cylinders), NO can also be generated by discharge. Among them, the pulsed arc discharge can realize the preparation of NO at any time and solve the problems of decompression and storage of conventional NO gas supply. In this paper, the clinical application of NO, discharge technology, and removal methods of nitrogen dioxide (NO2) were reviewed.

Expressions of TREM-1 and COX-2 in rectal carcinomaand their relationship with prognosis / 西安交通大学学报(医学版)

Objective To detect the differences of triggering receptor expressed on myeloid cells-1 (TREM-1) and cyclo-oxygenase-2 (COX-2) expressions in rectal cancer tissues and carcinoma adjacent tissues so as to explore the relationship between the two factors and clinical pathological characteristics and their effects on the patients` survival.Methods The expressions of TREM-1 and COX-2 were analyzed in 68 cases of rectal cancer tissues and 58 cases of carcinoma adjacent tissues with the method of immunohistochemical staining.We made a regular follow-up of the patients, analyzed the relationship between the two factors and prognosis of rectal cancer.Results The positive expression rates of TREM-1 and COX-2 in rectal cancer tissues were higher than those in carcinoma adjacent tissues (P<0.05).The expression of TREM-1 was related to lymph node metastasis, while COX-2 was related to pathological stage and lymph node metastasis (P<0.05).However, the two factors were not related to age, sex, histological differentiation or tumor size.The expressions of the two factors were positively correlated (r=0.550, P<0.001).The overall survival (OS) of TREM-1 and COX-2 positive expression groups was shorter than that of the negative groups (P<0.05).Cox multiple regression analysis showed that the expression of TREM-1, pathological stage, lymph node metastasis and tumor size affected the prognosis.Conclusion The expressions of COX-2 and TREM-1 in rectal cancer increase, suggesting that the two factors may promote the development and lymph node metastasis of rectal cancer, and the expressions of the two factors are related to the patients` poor prognosis.

Clinicopathological Significance and Relevant Molecular Mechanisms of Beclin 1 in Gastric Cancer / 中国医科大学学报

Objective to explore the role of Beclin 1 in gastric carcinogenesis and subsequent progression. Methods MkN28 cells were trans-fected with Beclin 1-expressing plasmid,and then the proliferation and cell cycle was measured by CCk-8 and PI staining. Beclin 1 expression was examined by immunohistochemistry and in situ hybridization on tissue microarrays containing gastric cancers,adjacent non-neoplastic mucosa,and metastatic lymph node. the correlation with the tumorgenesis,clinicopathological and prognostic parameters was analyzed. Results Beclin 1 overex-pression resulted in G2 arrest of MkN28 cells and reduced the proliferation. Beclin 1 mRNA was highly expressed in gastric cancer than matched mu-cosa by ISH(P < 0.05). Beclin 1 was highly expressed in male than female patients with gastric cancer(P < 0.05). the elder patients with gastric cancer had higher Beclin 1 expression than younger ones(P < 0.05). the diffuse-type carcinomas showed less Beclin 1 expression than intestinal and mixed type ones(P < 0.05). kaplan-Meier analysis indicated that Beclin 1 expression was positively correlated to favorable prognosis of the can-cer patients(P < 0.05). Conclusion Beclin 1 expression is closely linked to pathogenesis,metastasis and differentiation of gastric cancer. Beclin 1 might be employed to indicate the favorable prognosis of gastric cancer patients and regarded as a target of gene therapy.

Roles of BTG3 Expression in Gastric Cancer and Mechanism for Its Tumor Suppression Function / 中国医科大学学报

Objective To clarify the clinicopathological significance and the reversing effects of BTG3 expression on the aggressive phenotype in gastric cancer. Methods BTG3 expression was detected in gastric cancer tissues by on tissue microarray and immunostaining. BTG3?expressing plasmid was transfected into MKN28 and MGC803 cells,the proliferation,cell cycle,differentiation and autophagy were analyzed by CCK?8,PI staining,alkaline phosphatase activity and GFP?LC?3B transfection,respectively. Results BTG3 overexpression inhibited cell proliferation,in?duced S/G2 arrest,differentiation and autophagy in both cells(P<0.05). BTG3 expression was decreased in gastric cancer in comparison with the adjacent mucosa(P<0.05),and positively correlated with venous invasion and dedifferentiation of the cancers(P<0.05). Conclusion BTG3 ex?pression contributes to gastric carcinogenesis and subsequent progression. BTG3 overexpression can reverse the aggressive phenotypes,which could be employed as a potential target for gene therapy of gastric cancer.

Establishment of an HBV chronic hepatitis B infection mouse model by vivo transduction of HBV cccDNA / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To generate a mouse model of chronic hepatitis B (CHB) infection by performing in vivo transduction of hepatitis B virus (HBV) covalently closed circular (ccc)DNA.</p><p><b>METHODS</b>Nude mice were injected with HBV cccDNA at doses of 1.5, 1.0 or 0.5 mug/ml. A control group was generated by giving equal injection volumes of physiological saline. The serum levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) on post-injection days 1 and 3, weeks 1-6, 8 and 10 were assayed by reflection immunoassay. At post-injection week 10, all animals were sacrificed and liver tissues were collected. Copies of HBV DNA in serum and liver tissue were detected by real-time PCR. HBV antigens in liver tissue were detected of by immunohistochemistry. Pathological analysis of liver tissue carried out with hematoxylin-eosin staining. Linear correlation of data was determined by statistical analysis.</p><p><b>RESULTS</b>HBsAg and HBeAg were detected in sera from all three groups of cccDNA-injected mice staring at post-injection day 1 and lasting through week 10. The levels of HBsAg over the 10-week period showed two patterns of increase-decrease;the lowest level was detected at week 4 and the highest level was detected at week 8. In contrast, the levels of HBeAg over the 10-week period showed three patterns of increase-decrease; the lower levels were detected at weeks 2 and 4 and the higher levels at weeks 3 and 6. HBV DNA copies in liver tissues showed a cccDNA dose-dependent descending trend over the 10-week study period (1.5 mug/ml:1.14E+07 ± 6.51E+06 copies/g, 1.0 mug/ml:9.81E+06 ± 9.32E+06 copies/g, and 0.5 mug/ml:3.72E+06 ± 2.35E+06 copies/g; Pearson's r =0.979). HBV DNA copies in sera showed the pattern of 1.0 mug/ml cccDNA more than 1.5 mug/ml cccDNA more than 0.5 mug/ml cccDNA, and in general were higher than those detected in the liver tissues. Liver tissues from all cccDNA-injected mice showed positive immunohistochemistry staining for both HBsAg and HBeAg. HE staining showed that the liver tissues of all cccDNA-injected mice had severe fatty and vacuolar degeneration and less obvious structure of liver lobules (compared to the liver tissues from control mice).</p><p><b>CONCLUSION</b>The CHB mouse model successfully established in this study by in vivo transduction of HBV cccDNA may represent a useful tool to study the pathogenic mechanisms and potential antiviral treatments of human CHB.</p>

Comparison of real-time genotyping and quantitative PCR,multiplex-PCR and sequence analysis for hepatitis B virus genotypes B and C / 中华微生物学和免疫学杂志

Objective To evaluate the real-time genotyping and quantitative PCR(RT-GQ-PCR)method by comparing it with direct sequence analysis and the multiplex-PCR method.Methods RT-GQ-PCR,direct sequence analysis and the multiplex-PCR method were used to detect HBV genotypes of 113 patient samples with HBV-DNA positive.ResultsThe detection rate of RT-GQ-PCR and direct sequence analysis was 100%,and the multiplex-PCR is 94.69%.The concordance between RT-GQ-PCR and the multiplex-PCR is perfect(Kappa value =0.915),and the consistency of RT-GQ-PCR and direct sequence analysis is pretty good(Kappa value = 0.742),specially at detecting single genotype.Twenty-eight samples with genotypes B and C dual infections were detected by RT-GQ-PCR,but only 19 samples by the multiplexPCR and 13 samples by direct sequence analysis.Conclusion The RT-GQ-PCR is convenient,rapid and accurate in HBV genotyping,especially more sensitive than direct sequence analysis and the multiplex-PCR for detecting dual genotypes.The method is applicable for large-scale epidemiological study.

Study on the characteristics and hepatotropism of the negative regulatory element of the HBVnt453-250 / 中华微生物学和免疫学杂志

Objective To analyze the characteristics and hepatotropism of this negative element HBVnt453-250 sequence.Methods pHBv453-250,pHBV250-453.plucHBV453-250 and plucHBV250-453 were constructed,with luciferase and enhanced green fluorecence protein(EGFP)gene as the reporter gene,respectively.After transfection of HepG2 cells with these plasmids,luciferase assays,real-time PCR and western blot assays were used to detect the gene transcription and expression level.The SV40 promoter of pGL3 control and pHBV453-250 were replaced by the cytomegalovirus early promoter,resulting in plasmids pCMVcontrol(luc)and pCMV453-250(luc).Results Compared with pHBV453-250,the mutant plasmids.with the inhibitory element inserted in difierent site or inverted orientation.exerted similar downregulation of Juciferase gene transcription and expression.Western blot analysis demonstrated the similar repression when EGFP was used as the reporter gene.By transfeeted to HepG2 cell line,the plasmid pCMV453-250(1UC)could reduce lneiferase activity(36.56%)compared with pCMLcontrol(luc).When the plasmids plueHBV453-250 and plucHBV250-453 were transfected to non-liver cell lines(A549,HeLa),luciferase gene was expressed weakly,compared with that of pGL3control(P＜0.05).Conclusion The inhibitory effect of HBVnt453-250 sequence acted in both orientation-and position-independent manners,and had no promoter selectivity and funotioned in hepatocyte-independent manner.

Association of polymorphisms in transcription factor 7-like 2(TCF7L2) gene with type 2 diabetes in Chinese Han population / 中华内分泌代谢杂志

Objective To study the association of transcription factor 7-like 2(TCF7L2)polymorphisms with tvpe 2 diabetes mellitus in Chinese Han population. Methods Two polymorphisms (rs7903146 and rs12255372)of TCF7L2 gene were genotyped in 446 patients with type 2 diabetes mellitus(T2DM group)and 303 normal subiects (NC group) by PCR-restriction fragment length polymorphism(PCR-RFLP).Waist circumference.body mass index,plasma glucose,serum insulin,lipid profiles,high-sensitivity C-reactive protein and non-esterified fatty acid were measured.Homeostasis model assessment of insulin resistance(HOMA-IR)and β-cell function(HOMA-β)were calculated.Results (1) In T2DM group,T allele frequency and CT,TY geno tvpe frequeneies of rs7903146 were significantly higher than those in NC group(0.093,0.150,0.018 vs 0.043, 0.079,0.003,respectively,a11 P<O.O 1).Logistic regression analysis showed that the CT/TT genotype was a risk factor of tvpe 2 diabetes(OR=2.25,95%CI 1.39-3.62,P=0.001)and was associated with the decrease of insulin secretion. (2) No significant association was observed in vs12255372 alleles and genotypes with type 2 diabetes mellitus.Conclusion These results indicate that TCF7L2 might be one of the candidate genes for confe ring susceptibi lity to type 2 diabetes mellitus in the Chinese Han population.